This invention relates generally to ovens and, more particularly, to a combination oven using both radiant and microwave energy.
Known ovens are either, for example, microwave or radiant cooking type ovens. For example, a microwave oven includes a magnetron for generating RF energy used to cook food in the oven cooking cavity. Although microwave ovens cook food more quickly than radiant ovens, microwave ovens do not brown the food. Microwave ovens therefore typically are not used to cook as wide a variety of foods as radiant ovens.
Radiant cooking ovens include an energy source such as lamps which generate light energy used to cook the food. Radiant ovens brown the food and generally can be used to cook a wide variety of foods. Radiant ovens, however, cook foods slower than microwave ovens. It would be desirable to provide an oven which provides the speed advantages of microwave ovens yet also can be used to cook a wide variety of foods such as with radiant ovens.
In an exemplary embodiment of the invention, an oven includes both radiant cooking elements and a magnetron, or microwave, cooking element. The cooking elements are controlled to provide reduced cooking time as compared to known radiant ovens, yet a wide variety of foods can be cooked in the oven. The oven is operable in a speed cooking mode wherein both radiant and microwave cooking elements are utilized, in a microwave only cooking mode wherein only the magnetron is utilized for cooking, and a radiant only cooking mode wherein only the lamps are utilized for cooking.
In one aspect, the present invention relates controlling the power levels, and adjusting the power levels, in the speed cooking mode. More particularly, by controlling the power levels of the radiant cooking elements and the microwave cooking element, as well as the length of cooking time, desired cooking operations can be achieved.
In another aspect the present invention relates to adjusting the cooking time during cooking operations. Such adjustment is sometimes referred to herein as xe2x80x9cactive time adjustment.xe2x80x9d By enabling an operator to easily and quickly adjust the selected cooking time during cooking operation, the desired cooking can be achieved.
In yet another aspect the present invention relates to illuminating the cooking cavity during cooking operations, such as during microwave only mode cooking operations and cooking operations in which the lamps are not sufficiently energized to enable visualization of food in the cooking cavity. Since halogen lamps are used for radiant cooking, the oven door has a very dark glass window which does not enable visualization of the cooking cavity with typical microwave oven lighting. The present invention, however, provides for visualization of food in the cooking cavity during cooking operations by energizing a selected halogen lamp for a short period of time (i.e., 4 seconds) so that the cooking cavity is illuminated but negligible cooking is performed by the light energy output by the lamp.